Penetrometer



Aug. 19, 1952 c. M. HANSEN 2,607,218

PENETROMETER Enea sept. s, 1951 2 SHEETS- SHEET 1 la 106; 114113* 44 Tgp. 1. I

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PENETROMETER Filed Sept. 8, 1951 2 SHEETS- SHEET 2 1N VENTOR l Clare/10'@ Hansen IBYM+M ATTORNEY Patented Aug. 19, 1952 PEN ETROMETER Clarence M, Hansen,.Lansing, Mich., assigner to Research Corporation, New York, N. Y., a corporation of New York Application September 8, 1951Se1'ial-No.v245,710.

This inventionlrelates to an instrument for determining the physical characteristics ofv soils and similar substances.

A principal object of the invention is to` provide an instrument for measuring the forcerequired to effect the penetration of a probey into soil. for varying depths of penetration.

Another object of the inventionis to provide such a device for recording variationsvin` the force required for. penetration into soil for varying depths of penetration.

A further object is to provide a penetrometer thatis compact, light in weight and simple as to its parts whereby it may be readily transported and operated by one man. f

Another object of the invention is to provide a recording soil penetrometer that is readily adaptable for use in` various soily conditions.

These and other objects and advantages are provided by the recording soil penetrometer of the invention which generally comprises a probe shaft, a frame slidably mounted onA the probe shaft, resilient means transmitting Yto the probe shaft stress applied to the frame, a reference shaft parallel tothe probe shaft slidably mounted on the frame, means for recording the force transmitted from the frame to the probe shaft tc effect penetration of the probe for varying depths off penetration comprising an indicator member fixed to the probe shaft, a carriageV movably secured to the frame carrying a scale in cooperativerelation to the indicator'member, and drivel means connecting the carriage to the referenceshaft to move the carriage with'respect to the indicator member in response to relative movement of the frame and the reference shaft, said drive means including means for modulating: said movement of the carriage in response to relative movement ofthe frame and the probe shaft.

The invention will be more particularly described with reference to the illustrative embodiments thereof shown in the accompanying drawings` in which:

Fig. 1 is a front view of a form ofthe penetrometer with the. card carriage shown in broken lines to more clearly showY thel carriageY operating mechanism, and

Fig. 21s an enlarged detailed perspective view ofthe frame andthe carriage operating mech- Referring to thedrawings, I' isV theframe of the Lpenetrometer which comprises aV substantially rectangular guide member I2 providedwith openings I4'- andv I6l in its-opposite ends for slida'bly 2 receiving a probe shaft I8. A pair ,of` handles ZD'and acarriage support member 22 aresecured tothe sides of the guide member I2. The ends of the carriage support member 22 are provided with flanges 24 which support cylindrical tracks 25 between their extremities.

A carriage 28, shown in broken lines in the drawings, is slidably mounted on tracks 28 for reciprocatory motion between the flanged ends 24 of support member 22. The face ofthe carriage may be provided with a scale, or adapted to support a removable card type scale.

Probe shaft I8 in the preferred form of the invention is a cylindrical rod provdedfwth interchangeable probe points 30 for use in soils having different physical characteristics.

A calibrated coil spring 32 is positioned about the lower portion of the probe shaft I8 and engages at one end a ring flange 34 secured to the probe shaft and at the other end the lower end of the guide member I2. Thus the probe shaft is biased in a direction away from the supportingl frame Hl.

An indicator member 36, of any well known type,y is secured to the probe shaft between the ends of theguide member I2v by a clamp ring 38, whereby relative movement between the chart carriage and the probe shaft will be indicated on the face of the carriage or its attached scale.

A reference shaft 4U having a ground engaging foot 42 is slidably secured at its upper end to the frame I0 by means of a bracket 44 and at its lowery end by a bracket 46 secured to the probe shaftr I8.

It will be seen that when pressure is applied in a'. downward direction to handles 20 of the frame` IU, force is applied to the probe shaft by the. coil spring 32 which urges the probe shaft into the soil to be tested, thus while the foot of thereference shaft 40 remains substantially atV ground level the frame IQ and probe shaft move downwardly relative thereto. In order to record the depth of penetration of the shaft. i8 and thev corresponding' force, cooperating pulley systems, generally designated 48 and 49, connect the carriage 28 with the reference shaft and the probe shaft whereby the carriage is moved horizontally'past the indicator 36 a predetermined increment proportional to the depth of penetration ofthe probe while at the same time it moves verticallypast the indicator a predetermined increment proportional to the relative movement 50 having cable grooves 52 and l54 with effective diameters of 3 and 1 attached to the carriage support member 22. A cable 56 loops around pulley groove 52 and has its ends fastened to the reference shaft by clamp rings 58 and 60. A second cable 62 of pulley system 48 is looped around pulley groove 54, and its ends pass through modulating pulleys 64 and 66 and are then fastened to plates 68 and 16 secured to the sides of the carriage 28. Thus as the frame I is moved downwardly relative to the reference shaft, carriage 28 is moved to the left with reference to the indicator member 36.

In order to compensate for the compression of by pulley system 48 is modulated by a second l pulley system 49.

Pulley system 49 generally comprises a pulley 14 having cable grooves 16 and 18 with effective diameters of 6 to 1 respectively attached to the guide member l2. An endless cable 80 is looped around pulley groove 16, through guide pulleys B2 and 84 and attached to the clamp ring v38l of the probe shaft. A second cable 86 is loopedl around pulley groove 18, through guide pulleys 88 and 90 and its ends are fastened to the modulating pulleys 64 and 66 respectively. Thus as frame I0 is moved downwardly relative to the probe shaft the movement of the carriage is modulated to compensate for compression of the coil spring 32.

From the foregoing description it will be seen that the present invention provides an improved soil penetrometer whereby the aims, objects and advantages of the invention are fully accomplished. It will be evident, however, that various modifications may be made in the construction of the device and in the form of the carriage driving mechanism. For example, the mechanical reduction of the pulley systems may be of any desired ratio depending on whether larger or smaller charts are desired or the pulley systems may be replaced with any suitable drive mechanism such as solid gear-ing employing racks and pinions.

It is further contemplated that the coil spring for transmitting force from the frame of the device to the probe shaft may be of any resilient material having a substantially straight line function within the operational range of the device, and that the resilient membermay be of the leaf or torsional spring type.

It is further contemplated that soil penetrometers constructed in accordance with the principles of the invention may be provided with a device to indicate or record the speed at which the probe is forced into the soil to be .tested whereby more accurate determinations of rphysical soil conditions may be obtained.

I claim:

1. A penetrometer comprising a probeshaft, a frame slidably mounted on said probe shaft, resilient means transmitting to the probe shaft stress applied to the frame, a referenceshaft parallel to the probe shaft slidably mounted on the frame, a ground engaging foot on said reference shaft, means for recording the f orce transmitted from the frame to the probe shaft to effect penetration of the probe for varying depths of penetration comprising an indicator member fixed to the probe shaft, a carriage movably secured to the frame carrying a scalein cooperative relation to the indicator member, and drive means connecting said carriage to said reference shaft to move the carriage with respect to the indicator member in response to relative movement of the frame and the reference shaft, said drive means including means for modulating the movement of the carriage in response to relative movement of the 'frame and the probe shaft.

2. A penetrometer comprising a probe shaft, a frame slidably mounted on said probe shaft, resilient means transmitting to the probe shaft stress applied to the frame. a reference shaft parallel to the probe shaft slidably mounted on the frame, a ground engaging foot on said reference shaft, means for recording the force transmitted from the frame to the probe shaft to effect penetration of the probe for varying depths of penetration comprising an indicator member nXed to the probe shaft, a carriage movably secured to the frame carrying a scale in cooperative relation to the indicator member, and drive means for said carriage comprising a first -pulley system connecting said carriage to said reference shaft to move the carriage with respect to the indicator member in response to relative movementfof the frame and the reference shaft and a second pulley system connecting the first pulleysystem with the probe shaft for modulating the movement of the carriage in response to relative movement of the frame and the probe shaft.

3. A penetrometer comprising a probe shaft, a frame slidably mounted for vertical reciprocatory movement on said probe shaft, resilient means transmitting to the probe shaft stress applied to the frame, said resilient means comprising a coil spring, one end of said spring engaging the frame and the other end engaging the probe shaft, whereby the pro'be shaft is urged away from the frame, means for recording the force transmitted from the frame to the probe shaft to effect penetration of the probe for varying depths of penetration comprising a marking member fixed to the probe shaft, a carriage movably secured to the frame carrying a scale in cooperative relation to the markingV member, a reference shaft parallel to the probe shaft slidably mounted on the frame, a ground engaging foot on said' reference shaft, and drive means .connecting said carriage to said reference shaft movement of the frame Aand the prorbe shaft.

4. A penetrometer comprising a probe shaft, a frame slidably mounted for vertical reciprocatory movement on said probe shaft, resil-ient means transmitting to the probe shaft stress applied to the frame, said resilient means comprising a coil spring, one endof` said spring engaging the frame and the other end engaging the probe shaft, whereby the probe shaft is.urged away from thevframe, means for recording the force transmitted from the frame to the probe shaft to effect penetration of the probe for varyingdepths of penetration comprising a marking member fixed to the Iprobe shaft, a carriage movably secured to the frame carrying a scale in cooperative relation to the marking member a reference shaft parallel tothe probe shaft sl'idably mounted on the frame, a ground engaging foot on said reference shaft, and drive means for 5 said carriage comprising a flrst pulley system connecting said carriage to said reference shaft to move the carriage with respect to the marking member in response to relative movement of the frame and the reference shaft, and a second -pulley system connecting the first pulley system with the probe shaft for modulating the movement of the carriage in response to relative movement of the frame and the probe shaft.

CLARENCE M. HANSEN.

REFERENCES CITED The following references are of record in the le of this patent:

Number Number 6 UNITED STATES PATENTS Name Date Foster June 5, 1934 Van Der Meer Sept. 20, 1938 Nadal et al Apr, 28, 1942 FOREIGN PATENTS Country Date Germany Apr. 25, 1933 

